Pivoting device of a watch movement train element



June 13, 1967 3,324,646

' PIVOTING DEVICE OF A WATCH MOVEMENT TRAIN ELEMENT JEAN'CLAUDE SCHNEIDER Filed July 14, 1965 mu I United States Patent 3,324,646 PIVOTING DEVICE OF A WATQH MOVEMENT TRAIN ELEMENT Jean-Claude Schneider, La Chaux-de-Fonds, Switzerland, assignor to Fabrique dHorlogerie Chs. 'D'ssot et Fils S.A., Le Locle, Switzerland, a company Filed July 14, 19.65, Ser. No. 471,918 Claims priority, application Switzerland, Aug. 7, 1964, 10,350/64 3 Claims. (Cl. 58-140) The present invention relates to a pivoting device of a watch movement train element having at least two active elements carried on a shaft.

In the heretofore known watch movements some of the train elements comprise only one active element such as for example the intermediate or setting wheel or the crown or transmission wheel, which generally are pivoted on studs provided on the bottom plate or on another element of the frame. On the contrary the train elements such as those of the gear train, which generally comprise two active elements, namely a wheel and a pinion present at both ends of their shaft pivots engaged in bearings mounted in the frame elements which hold the train element in place.

The prime object of the present invention is to realize a pivoting device of simple construction adapted to reduce to a large extent the bending moment to which the shaft ends are submitted.

To this end in the pivoting device according to the present invention the shaft comprises at least at one of its ends an axial bed forming a bearing engaged on a pivot stem protruding from a frame element of the movement.

Other features and advantages of the invention will become apparent from the description now to follow, of several embodiments thereof, given by way of example only, and in which reference will be made to the accompanying drawings, in which:

FIGURES 1 and 2 are partial sectional views of a first and second embodiment respectively, and

FIGURES 3 and 4 are partial sectional views of the end of the shaft of a third and fourth embodiment respectively.

Referring to FIG. 1 reference numeral 1 designates a train element of the gear train of a watch movement comprising a wheel 2, a pinion 3, and a shaft 4. This train element is made of one piece. It'is carried by a plate 5 presenting a truncated projecting part 7. This part 7 presents a plane and annular upper face 8 and in the center of this face a bruise or dent 9 in the middle of which extends a bed 10 of cylindrical shape. A straight cylindrical stem 11 is forced into this bed 10 and protrudes for the major part of its length beyond the dent 9. This stem solely ensures the pivoting of the train element 1. To this end the latter presents at the lower end of its shaft 4 an axial bed which comprises a cylindrical conical entry 12 and an upper cylindrical portion 13 adjusted to the outer dimension of the stem 11. The entry 12 extends upwardly to the level of the upper face of the wheel 2 while the portion 13 which forms the bearing of the bearing block extends upwardly with respect to the shaft 4 to the pinion 3. The pinion 3 is adapted to cooperate with a wheel 14 the toothing of which meshes with that of the pinion 3 at a level inferior to that of the base of the bed 12, 13.

The portion of the bed 13 which forms the bearing of the bearing block is limited in height on the one hand by the upper portion of the stem 11 and on the other hand by the upper edge of the entry 12. This bearing extends in height between the wheels 14 and 2 so that the resultice-*- ant of the radial forces exerted onto the wheel 2 by an element (not represented) meshing with this wheel, and on the pinion 3 by the wheel 14 is transmitted to the stem 11 in form of a radial force. The bending moments compensate each other to a large extent. The stem 11 is sufiiciently stiif to withstand the radial force to which it is submitted without bending. It maintains the train element 1 in a perpendicular position with respect to the plate 5 and affords for its turning about its shaft.

The lower end of shaft 4 is constituted by an annular projection 15 extending upwardly beyond the level of wheel 2 around the entry of the bed 12 and resting on the abutment face 8. At its other end the shaft 14 presents V a conical abutment member 16 which is engaged within the conical bed of similar shape 17 provided in a projection 18 of the frame element 19. The latter forms one of the bridges of the movement. The bed 17 is adapted to guide and retain the abutment 16 .in the case of exaggerated shake of pivot 11 in its bearing.

FIGURE 3 illustrates another embodiment of the upper portion of shaft 4 and of the abutment 16. The upper face of this abutment is plain and the bridge 19 presents a projection 20 at its lower plane face which extends 0pposite the abutment 16 to limit the axial shake of the train element.

Still another modification is illustrated in FIGURE 4 in which the abutment 16' is formed by a plane annular face enclosing a conical bed provided in the end of shaft 4. In this case the bridge 19 has a conical projection 20'.

FIGURE 2 illustrates the pivoting of a balance 21 comprising a felloe 22 mounted on a shaft 23 and a table roller (not shown) also mounted on shaft 23. The balance is pivoted between the plate 5 and the bridge 19 and its shaft 23 traverses a profiled opening 24 made in a pallet bridge 25, the roller extending below this bridge. The plate 5 presents in the axis of an opening 26 a cylindrical bed 27 into the center of which is forced a pivot stem 28.

The bridge 19 also is provided with a bed 29 similar to the bed 27 into which is forced a stem 30 coaxially with respect to stem 28. At both ends of shaft 23 there are provided cylindrical beds 31 axially penetrating the shaft and provided with a conical entry 32 similar to the conical entry 12. The entries 32 extend to the corresponding end of the shaft and are limited by an annular face 33 which forms an axial abutment opposite the base of the beds 27 and 29, respectively.

The pivoting of the balance 21 is ensured by the two stems 28 and 30 fixed to the frame element by one of their ends, while the other is engaged in the cylindrical portionof the bed 31, which forms the bearing of the bearing block. Between these two ends each of the stems 28 and 30 has a tree portion of sufficient length to resiliently bend when the balance undergoes shock. The bending of the stems 28 and 30 is limited by the cylindrical lateral face of the shaft 23 abutting in the recesses 27 and 29. The described pivoting device thus forms a dampening bearing of extremely simple construction. The balance shaft may be made of plastic material and the stems 28 and 30 of steel, for example.

I claim:

1. In a pivoting device for a watch movement gear, a shaft having an axis of rotation and a pair of toothed members fixedly connected to said shaft and projecting radially with respect to said shaft axis at positions spaced along said shaft axis, a frame element adjacent one end of said shaft, a pivot stem protruding from said frame element, an abutment face provided on said frame element around said stem, an annular shoulder formed at said one end of said shaft and abutting said abutment face, and an axial passage forming a bed in said one end of said shaft about said stern, said axial bed including a cylindrical bearing surface engaging an upper portion of said stein, said bed including an entry portion of greater radial dimensions than said cylindrical bearing surface and extending axially from the lower end of said cylindrical bearing surface to said annular shoulder in spaced relation to said stem, said stern and shaft contacting each other solely along a contacting portion extending from the upper end of said stem to the lower end of said cylindrical bearing surface, said contacting portion being limited in axial extent to lie solely between the levels of said toothed members.

2. In a pivoting device as defined in claim 1 the combination further including, another frame element adjacent the other end of said shaft and having a stationary abutment element formed thereon, and a corresponding abutment element formed at the other end of said shaft cooperable with the stationary abutment element formed in said other frame element.

3. In a pivoting device as defined in claim 1 wherein said entry portion is partly cylindrical and partly conical.

References Cited UNITED STATES PATENTS 15 RICHARD B. WILKINSON, Primary Examiner.

GERALD F. BAKER, Examiner. i 

1. IN A PIVOTING DEVICE FOR A WATCH MOVEMENT GEAR, A SHAFT AN AXIS OF ROTATION AND A PAIR OF TOOTHED MEMBERS FIXEDLY CONNECTED TO SAID SHAFT AND PROJECTING RADIALLY WITH RESPECT TO SAID SHAFT AXIS AT POSITIONS SPACED ALONG SAID SHAFT AXIS, A FRAME ELEMENT ADJACENT ONE END OF SAID SHAFT, A PIVOT STEM PROTRUDING FROM SAID FRAME ELEMENT, AN ABUTMENT FACE PROVIDED ON SAID FRAME ELEMENT AROUND SAID STEM, AN ANNULAR SHOULDER FORMED AT SAID ONE END OF SAID SHAFT AND ABUTTING SAID ABUTMENT FACE, AND AN AXIAL PASSAGE FORMING A BED IN SAID ONE END OF SAID SHAFT ABOUT SAID STEM, SAID AXISL BED INCLUDING A CYLINDRICAL BEARING SURFACE ENGAGING AN UPPER PORTION OF SAID STEM, SAID BED INCLUDING AN ENTRY PORTION OF GREATER RADIAL DIMENSIONS THAN SAID CYLINDRICAL BEARING SURFACE AND 